Method and apparatus for cleaning thermometers



Jan. 3, 1961 J. CHANEY 2,957,120

METHOD AND APPARATUS FOR CLEANING THERMOMETERS Filed Nov. 7, 1956 FIG-182 34 17- J 70 T g 46 62 1LL61 64 i 13 r 52 54 55 56 v v v INVENTOR. 1JOHN L. CHANEY 5 7 53 ATTORNEYS METHOD AND APPARATUS FOR CLEANINGTHERMOMETERS John L. Chaney, Lake Geneva, Wis.

Filed Nov. 7, 1956, Ser. No. 620,827 Claims. (Cl. 134-22) This inventionrelates to the manufacture of thermometers, and is particularly directedto the cleaning of unfilled thermometer tubes, or the like, after thebulbs have been formed at one end of the tubes and while the other endsof the tube remain open.

In previous methods, thermometer tubes have been partially cleaned bythe use of weak cleaning liquids, such as alcohol, or the like. Thesemethods have been unsatisfactory because of the lack of cleaning powerof such liquids. The present invention permits the use of much strongercleaning liquids, such as muriatic, nitric or similar acid liquids,without danger of harming the operator.

Hence, an object of this invention is to provide a method and apparatusfor cleaning thermometer tubes with an acid liquid in a safe andthorough manner.

Another object of this invention is to provide a method of cleaningunfilled thermometer tubes or the like with an acid liquid by drainablysupporting a plurality of the tubes in inverted position with their bulbends at the top and with their open ends at the bottom in a pool formingzone, gravitationally draining an acid liquid from an acid liquid supplyzone into said pool forming zone and subjecting the surface of said acidliquid to a gaseous pressure sufiicient to drive the acid liquid intothe bulb ends of the tubes, returning the acid liquid from the poolforming zone to the acid liquid supply zone under gaseous pressure, andthereafter subjecting the tubes to an acid neutralizing and rinsingprocedure.

Another object of this invention is to provide a method of cleaningunfilled thermometer tubes or the like in which a plurality of the tubesare supported in inverted position with their bulb ends at the top andwith their open ends at the bottom in a pool forming zone, and intowhich zone a cleaning liquid is gravitationally drained from a cleaningliquid supply zone,'and then subjecting the surface of the cleaningliquid to a gaseous pressure sufiicient to drive the cleaning liquidinto the bulb ends, and then returning the cleaning liquid from the poolto the cleaning liquid supply zone under gaseous pressure.

Another object of this invention is to provide an apparatus for cleaningunfilled thermometer tubes or the like which comprises a rigidreceptacle, preferably cylindrical, and having a large vertical openingat its upper edge and having an acid-proof inner surface, a rigid coversubstantially horizontal when in use for sealing the opening and havingan acid-proof lower surface and having a valved inlet for gas underpressure and a valved gas outlet, means for moving said cover into andout of sealing engagement with the vertical opening, for example, by afluid pressure piston above the cover, one or more liquid tanks indrainable position into the receptacle with individual valved conduitdraining means for the liquid from the tank or tanks into the receptacleand with a valved drain conduit from adjacent the bottom of thereceptacle for returning liquid to the tank or tanks under gaseouspressure in the receptacle.

Further objects will become apparent as the description of the inventionproceeds in connection with the accompanying drawings in which:

Fig. 1 is a vertical elevation, partly in cross-section, showing anapparatus embodying this invention.

Fig. 2 is a partial cross-section taken along the line 22 of Fig. 1.

Fig. 3 is a cross-section of a thermometer tube in the process of beingcleaned.

Referring to the drawings which illustrate a preferred embodiment of theinvention, a rigid acid-proof receptacle 10 is preferably vertical andcylindrical, as shown in Fig. 1. It has a large vertical opening 11 atits top or upper edge and has an acid-proof inner surface or lining 12,and the outside of the tank may be painted with any acid-proof paint.For example, the lining 12 may be a inch layer of Vyfiex L-l0 or anyother well known material and the acid-proof paint may be Nukemite No.24, or any other well known material.

Means are provided for rigidly supporting the receptacle 10, preferablyat its upper edge. For example, an angle iron steel framework 13 maysupport a platform 14 having an opening 15 to receive the receptacle 10.The platform 14 supports the flange 16'of the receptacle 10 through themedium of a metal ring 17. If the receptacle 10 is 12 inches insidediameter and 26 inches long, for example, then the framework may be madeof 2-inch by 2-inch angle iron bars welded together. The platform 14 maybe one-half inch thick steel plate, and the receptacle 10 may be made ofIO-gauge steel.

A rigid, substantially horizontal, cover 20 has an acidproof lowersurface or lining 21 made of the same material as lining 12 and the mainpart of the cover 20 may be a three-quarter-inch thick steel plate. Ithas a valved inlet 22 connected to a supply of gas under pressure 23,such as compressed air. The cover 29 also has a valved gas outlet 24 forpermitting the escape of gas under pressure from the receptacle iii. Thevalves 25 and 26 may be manually operated or may be provided withsolenoids which may be energized by electrical buttons or by anelectrical timer, not shown, which may also similarly control all of theother valves herein described, to produce the sequences of operationherein described.

A fluid pressure piston in the cylinder 27 above the cover 20 isconnected thereto by the plunger 28 to move the cover into and out ofsealing engagement with the vertical opening 11 and may press the cover20 down on the opening 11 with a force of between 2500 and 3000 lbs. Thecylinder 27 may be connected to a source of liquid under pressurethrough the pipe 30 and this liquid may be returned to the sourcethrough the pipe 31. The manually operated or solenoid operated valve 32selectively introduces the liquid from pipe 30 into the pipe 33 at thesame time that liquid is being returned from the pipe 34 into the pipe31, or vice versa. The valve 32 in another position can also close allconnections between the pipes 30, 31, 33 and 34. The pipe 34 feedsliquid above the piston while the pipe 33 feeds the liquid below thepiston to move the cover 20 down and up to seal or uncover the opening11.

A plurality of cleaning fluid tanks 40, 41 and 42 are supported inposition to discharge liquid by gravity into the receptacle 10. Conduits43, 44, and 45 drain from the respective tanks 40, 41 and 42 into thereceptacle 10 through the medium of the common pipe 46. These conduitshave individual valves 47, 48, and 49 for controlling the flow of liquidfrom each of the tanks into the receptacle 10. These valves may bemanually opened and closed or they may be automatically closed bysolenoids controlled by the timer or push-button construction previouslydescribed. Individual return conduits 50, 51 and 52 return liquid fromadjacent the bottom of receptacle through the common return pipe 53,under the control of individual return valves 54, 55 and 56 into returnpositions, preferably at the upper parts of the respective tanks 46, 41and 42. A drain conduit 57 may be controlled by valve 58, manual orsolenoid operated, for draining any liquid, as desired, into any wastepipe or any other place of disposal. The tank 40, and the tanks 41 and42, if desired, may be protected by an acid-proof lining 59 similar inconstruction and material to lining ll2. Removable covers 66 areprovided for the tanks 40, 41 and 42. Muriatic, nitric, or othersuitable acid liquid, of 20% strength or the like, is placed in tank 40.An acid neutralizing liquid, such as soda water or other alkalinematerial, is placed in tank 41, and a rinsing liquid, such as distilledwater, is placed in tank 42.

An acid-proof pervious container, adapted to permit the flow of liquidinto and out of such container includes one or more baskets 61 made ofplastic material, for example, and are adapted to receive unfilledthermometer tubes in inverted positions, the tubes 62 having their bulbs63 at the top and their open ends 64 downward. The basket or baskets 61are insertable and removable from the container 16 through the largevertical opening 11 when the cover an is in its upper position.

In the practice of the method and operation of the apparatus, aplurality of thermometer tubes 62 are supported in inverted position bythe baskets 61 with their bulb ends at the top and open ends at thebottom. After the baskets have been inserted in the receptacle 10, theacid liquid from the tank or acid liquid supply 40 is drained by gravitythrough the pipes 43 and 46 by the opening of valve 47 into the poolforming zone, or lower part of the recceptacle lit The pipes 43 and 46,as well as any other pipes so desired, may be lined with acidproofmaterial of a character similar to lining 12. The cover 2%} is moved tothe lower position by the action of the piston in cylinder 27 eitherbefore or after the introduction of the acid into the receptacle 10. Agaseous medium under pressure, such as air under 15 lbs. gauge, is thenintroduced from the supply hose 23 through the pipe 22 by the opening ofvalve 25 While all other valves are closed. This subjects the surface ofthe acid liquid in the pool forming zone to a gaseous pressuresuflicient to drive the acid liquid through the open ends into the bulbends, as illustrated in Figure 3. This is sufficient to dissolve andclean any impurities which are likely to be in the tubes. Thereafter theacid liquid is returned to the tank or acid liquid supply zone 40through the pipes 53 and Si) by the opening of valve 54. Much of theacid liquid in tubes 62 is forced out by the air under pressure trappedin the bulbs 63. At this time the valve 25 may remain open, or may havebeen closed, if the amount of air within the receptacle 2% is sufficientto lift the acid liquid into the tank 46. Thereafter the valves 25 and54 are closed, and any slight amount of acid liquid remaining in thetubes 62 and tank 40 may be allowed to drain or blow through the pipe 57by the opening of valve 58 for a sufficient length of time to permitsuch drainage, after which the valve 58 is reclosed. Thereafter the gasoutlet valve 26 is opened to relieve all gaseous pressure within thereceptacle 10.

The acid neutralizing liquid is then drained from the neutralizingliquid supply zone or tank 41 through the pipes 44 and 46 by the openingof valve 48 into the pool forming zone of the receptacle i0. Thereafterthe valve 48 is closed along with valve 26 and the valve 25 is opened tosubject the surface of the acid neutralizing liquid to the gaseouspressure from the pipe 22 such as air under 15 lbs. gauge pressure, asbefore. This drives the acid neutralizing liquid into the bulbs 63 ofthe tubes 62 to neutralize the acid in the tubes and bulbs after whichthe liquid is drained from the tubes and receptacle it and returned tothe tank 41 under gaseous, pressure in a manner similar to thatpreviously described with respect to the tank 40. Any excess liquidremaining in the tubes or receptacle may also be blown or drainedthrough the valve 58 as previously described.

Thereafter the valve 58 is closed and valve 26 is opened, and therinsing liquid may be introduced into the pool forming zone ofreceptacle 10 from the tank or liquid supply zone 42 and may be returnedthereto after pressurizing in a manner similar to that previouslydescribed with respect to the acid liquid and acid neutralizing liquidoperations. On the other hand, if it is desired not to return thedistilled water from the receptacle 10 to the tank 42, the valve 56 neednot be opened and the valve 58 may be opened to allow the entirecontents of distilled water to be blown or drained from the receptacle10 and tubes 62 to the waste drain 57.

It is to be noted that whenever there is a cleaning liquid in thecleaning liquid supply zone or lower part of receptacle 10, and when thegaseous pressure is applied to the surface of such liquid, then suchliquid rises through the temperature indicating passageway 70 of thetube 62 into the bulb 63. The 15 lb. pressure indicated is suflicient tocause compression of the air within the tube 62 to such an extent thatthe liquid rises approximately to fill half the bulb 63 which issufficient to cause a full cleaning of the tube. Naturally a higher airpressure causes a higher rise of liquid in the bulb 63. When thepressure is relieved by the opening of any of the valves 54, 55, 56and/or 26 or 58, the air trapped at the top of the bulb 63 forces theliquid out of the tube 62, so that the tube is substantially empty whensuch pressure is relieved. The volume content of the bulb 63 ordinarilyis about 10 times the volume content of the passageway 70, and this highratio of volume content permits the rise of the liquid within the bulb63 under the pressure conditions previously described.

Occasionally, when liquid is expressed from tube 62 by the action of thecompressed air contained within bulb- 63, the expression is incomplete,a small quantity of liquid being left near the small end of tube 62.Since the possibility of contamination, as well as useless loss of rinseliquids, occurs when tubes 62 contain small quantities of acid, it isoften advantageous to include an additional liquid expressing stepbetween successive rinses to insure that tubes 62 are effectivelystripped of liquid remaining therein. The additional step comprisessubjecting tubes 62 to an atmosphere of clean, compressed airintermediate each, or following any one of the rinsing steps to compressthe air contained within the tubes The increase in pressure within thetubes is accomplished by filling the rinsing zone, chamber 10, withcompressed air. Upon release of the gas pressure from container 10 anyremaining liquid will be exhausted from the tube.

After the tubes have been subjected to the action of the acid liquid,the acid neutralizing liquid, and the rinse liquid, and all of theliquids have been drained out of the tubes 62 and receptacle 10, thepressure is relieved by the opening of valve 26, if necessary, and thenthe cover 20 is moved to its upper position by the action of the pistonin cylinder 27 and the trays 61 and tubes 62 in them are removed fromthe receptacle 10 through the opening 11. Thereafter the tubes arefilled with temperature indicating liquid and the open ends 64 aresealed in any well-known manner.

The method and apparatus as herein disclosed is particularly effectivein cleaning thermometer tubes in large quantities. The use of strongcleaning liquids is rendered harmless to the operator by the foregoingfeatures of the invention.

While the embodiment of the invention herein disclosed is that which isnow preferred, and while certain materials have been mentioned andcertain pressures have been suggested, it is to be understood that theseare illustrative in nature, and may be varied within the scope of theclaims which follow.

I claim:

1. An apparatus for cleaning unfilled thermometer tubes comprising, areceptacle having a large vertical opening at its upper end, means forsupporting said receptacle in an upright position, a cover for saidopening movable in and out of sealing engagement therewith, saidreceptacle having a valved inlet for gas under pressure and a valved gasoutlet, an acid liquid tank and an acid neutralizing liquid tank eachbeing in position to discharge liquid into said receptacle by gravity,individually valved conduits discharging by gravity from each of saidtanks into said receptacle, a valved conduit connecting the bottom ofsaid receptacle to each of said tanks for returning liquid from saidreceptacle to its respective tank under the influence of gaseouspressure within said receptacle, and a pervious container insertable andremovable through said large vertical opening adapted to supportunfilled thermometer tubes in inverted positions with their bulbs at thetop and their open ends at the bottom and submerged in the liquid insaid receptacle.

2. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted posithionwith their bulb ends at the top and with their open ends downward in apool forming zone, flowing an acid liquid from an acid liquid supplyzone into said pool forming zone and covering the open ends of saidtubes with said acid liquid subjecting the surface of said acid liquidto a gaseous pressure sufficient to drive said acid liquid through saidopen ends into said bulb ends with resultant compression of the gasentrapped in said bulb ends, withdrawing said acid liquid from said poolforming zone and relieving the pressure thereon to effect removal ofsaid liquid from said tubes by expansion of said entrapped gas,introducing an acid neutralizing liquid into said pool forming zone andsubjecting the surface of said acid neutralizing liquid to a gaseouspressure suflicient to drive said acid neutralizing liquid into saidbulb ends, and relieving said pressure and withdrawing said acidneutralizing liquid from said tubes and pool forming zone.

3. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted position withtheir bulb ends at the top and with their open ends downward in a poolforming zone, supplying a cleaning liquid from a cleaning liquid supplyzone into said pool forming zone and covering the open ends of saidtubes with said cleaning liq uid, subjecting the surface of saidcleaning liquid to a gaseous pressure sufiicient to drive said cleaningliquid through said open ends into said bulb ends against the pressureof the gas entrapped therein, releasing said pressure on said liquid,and withdrawing said liquid from said pool forming zone to cause theliquid in said tubes to drain under the pressure of the gas trapped insaid bulbs.

4. The method of cleaning unfilled thermometer tubes which comprises.drainably supporting a plurality of said tubes in inverted position withtheir bulb ends at the top and with their open ends at the bottom in apool forming zone, gravitationally and sequentially draining a pluralityof cleaning liquids from a plurality of cleaning liquid supply zonesinto said pool forming zone and covering the open ends of said tubeswith said cleaning liquids, sequentially subjecting the surface of eachof said liquids to gaseous pressure sufficient to drive each of saidcleaning liquids through said open ends into said bulb ends, andsequentially relieving said pressure and returning each of said cleaningliquids from said poo] forming zone to the respective cleaning liquidsupply zones.

5. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted position withtheir bulb ends at the top and with their open ends downward in a poolforming zone, gravitationally draining an acid liquid from an acidliquid supply zone into said pool forming zone to cover the open ends ofsaid tubes with said acid liquid, subjecting the surface of said acidliquid to a gaseous pressure suflicient to drive said acid liquidthrough said open ends into said bulb ends, returning said acid liquidfrom said pool forming zone to said acid liquid supply zone, filling thepool forming zone with an atmosphere of compressed gas, and thereafterreleasing said compressed atmosphere so that the pool forming zonereturns to substantially atmospheric pressure with resultant strippingof remaining liquid from the tubes.

6. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted position withtheir bulb ends at the top and with their open ends at the bottom in apool forming zone, gravitationally and sequentially draining a pluralityof cleaning liquids from a plurality of cleaning liquid supply zonesinto said pool forming zone to cover the open ends of said tubes withsaid cleaning liquids, sequentially subjecting the surface of each ofsaid liquids to gaseous pressure sufiicient to drive each of saidcleaning liquids through said open ends into said bulb ends,sequentially returning each of said cleaning liquids from said poolforming zone to the respective cleaning liquid supply zones, and fillingand exhausting the pool forming zone with an atmosphere of compressedgas intermediate each of said sequentially performed liquid cleaningsteps to strip the remaining liquid from the tubes.

7. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted position withtheir bulb ends at the top and with their open ends at the bottom in apool forming zone, gravitationally and sequentially draining a pluralityof cleaning liquids from a plurality of cleaning liquid supply zonesinto said pool forming zone and covering the open ends of said tubeswith said cleaning liquids, sequentially subjecting the surface of eachof said liquids to gaseous pressure sufiicient to drive each of saidcleaning liquids through said open ends into said bulb ends,sequentially returning each of said cleaning liquids from said poolforming zone to the respective cleaning liquid supply zones, and fillingand exhausting the pool forming zone with an atmosphere of compressedgas after the compression of the last liquid cleaning to strip theremaining liquid from the tubes.

8. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted position withtheir bulbs at the top and with their open ends downward in a poolforming zone, admitting a cleaning liquid into said zone to cover saidopen ends with said cleaning liquid, subjecting the surface of saidliquid to a gaseous pressure suflicient to drive said liquid throughsaid open ends into said bulbs with the resultant compression of the gastrapped in said bulbs,

removing said liquid and said pressure from said zone to elfect thesubstantial removal of said liquid from said tubes by the expansion ofsaid entrapped gas, and subjecting said tubes to a gaseous pressure andreleasing said pressure to effect the purging of any remaining liquidfrom said tubes.

9. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted position withtheir bulbs at the top and with their open ends downward in a poolforming zone, admitting a cleaning liquid into said zone to cover saidopen ends with said cleaning liquid, subjecting the surface of saidliquid to a gaseous pressure sufiicient to drive said liquid throughsaid open ends into said bulbs with the resultant compression of the gastrapped in said bulbs, removing said liquid from said zone under theinfluence of said pressure, removing said pressure to effect thesubstantial removal of said liquid from said tubes by the expansion ofsaid entrapped gas, and subjecting said tubes to a gaseous pressure andreleasing said'pressure to effect the purging of any remaining liquidfrom said tubes.

10. The method of cleaning unfilled thermometer tubes which comprises,drainably supporting a plurality of said tubes in inverted position withtheir bulbs at the top and With their open ends downward in a poolforming zone, admitting a cleaning liquid into said zone to cover saidopen ends With said cleaning liquid, subjecting the surface of saidliquid to a gaseous pressure suflicient to drive said liquid throughsaid open ends into said bulbs with the resultant compression of the gastrapped in said bulbs, removing said liquid from said Zone under theinfluence of said pressure, and removing said pressure to effect theremoval of said liquid from said tubes by the expansion of saidentrapped gas.

References Cited in the file of this patent UNITED STATES PATENTSBrandwood Mar. 7, 1916 Raymond Aug. 15, 1916 Fish Jan. 20, 1920 Bots May6, 1924 Trowbridge June 28, 1932 Perkins Oct, 30, 1934 Redin June 26,1951 Daley Dec. 2, 1952 Nordling Dec. 18, 1956 Prickett Sept. 2, 1958

1. AN APPARATUS FOR CLEANING UNFILLED THERMOMETER TUBES COMPRISING, ARECEPTACLE HAVING A LARGE VERTICAL OPENING AT ITS UPPER END, MEANS FORSUPPORTING SAID RECEPTACLE IN AN UPRIGHT POSITION, A COVER FOR SAIDOPENING MOVEABLE IN AND OUT OF SEALING ENGAGEMENT THEREWITH, SAIDRECEPTACLE HAVING A VALVED INLET FOR GAS UNDER PRESSURE AND A VALVED GASOUTLET, AN ACID LIQUID TANK AND AN ACID NEUTRALIZING LIQUID TANK EACHBEING IN POSITION TO DISCHARGE LIQUID INTO SAID RECEPTACLE BY GRAVITY,INDIVIDUALLY VALVED CONDUITS DISCHARGING BY GRAVITY FROM EACH OF SAIDTANKS INTO SAID RECEPTACLE, A VALVED CONDUIT CONNECTING THE BOTTOM OFSAID RECEPTACLE TO EACH OF SAID TANKS FOR RETURNING LIQUID FROM SAIDRECEPTACLE TO ITS RESPECTIVE TANK UNDER THE INFLUENCE OF GASEOUSPRESSURE WITHIN SAID RECEPTACLE, AND A PERVIOUS CONTAINER INSERTABLE ANDREMOVABLE THROUGH SAID LARGE VERTICAL OPENING ADAPTED TO SUPPORTUNFILLED THERMOMETER TUBES IN INVERTED POSITIONS WITH THEIR BULBS AT THETOP AND THEIR OPEN ENDS AT THE BOTTOM AND SUBMERGED IN THE LIQUID INSAID RECEPTACLE.
 2. THE METHOD OF CLEANING UNFILLED THERMOMETER TUBESWHICH COMPRISES, DRAINABLY SUPPORTING A PLURALITY OF SAID TUBES ININVERTED POSITION WITH THEIR BULB ENDS AT THE TOP AND WITH THEIR OPENENDS DOWNWARD IN A POOL FORMING ZONE, FLOWING AN ACID LIQUID FROM ANACID LIQUID SUPPLY ZONE INTO SAID POOL FORMING ZONE AND COVERING THEOPEN ENDS OF SAID TUBES WITH SAID ACID LIQUID SUBJECTING THE SURFACE OFSAID ACID LIQUID TO A GASEOUS PRESSURE SUFFICIENT TO DRIVE SAID ACIDLIQUID THROUGH SAID OPEN ENDS INTO SAID BULB ENDS WITH RESULTANTCOMPRESSION OF THE GAS ENTRAPPED IN SAID BULB ENDS, WITHDRAWING SAIDACID LIQUID FROM SAID POOL FORMING ZONE AND RELIEVING THE PRESSURETHEREON TO EFFECT REMOVAL OF SAID LIQUID FROM SAID TUBES BY EXPANSION OFSAID ENTRAPPED GAS, INTRODUCING AN ACID NEUTRALIZING LIQUID INTO SAIDPOOL FORMING ZONE AND SUBJECTING THE SURFACE OF SAID ACID NEUTRALIZINGLIQUID TO A GASEOUS PRESSURE SUFFICIENT TO DRIVE SAID ACID NEUTRALIZINGLIQUID INTO SAID BULB ENDS, AND RELIEVING SAID PRESSURE AND WITHDRAWINGSAID ACID NEUTRALIZING LIQUID FROM SAID TUBES AND POOL FORMING ZONE.